Disk bit



July 14, 1936.

Fig. 1

Fly. 2 V

J. H. HOWARD 2,047,559

DISK BIT Filed June 17, 1935 2 Sheets-Sheet 1 Fig.3

as 22 a7 /a 42 5/ /n vemor Job/7 Hon/0rd oer Afforney Patented July 14, 1936 Nl'l'ED STATES} PATENT OFFICE DISK BIT Application June 17, 1933, Serial No. 676,357

16 Claims.

This invention relates to a rotary well drilling bit, and relates more particularly to a disk bit. It is a general object of the invention to provide a disk bit that is effective in operation and that is particularly simple and easy to assemble.

Another object of the invention is to provide a disk bit that includes a plurality of disk cutters rotatably mounted on a shank in a simple, practical and dependable manner.

Another object of the invention is to provide a disk bit of the character mentioned in which the cutters may be delivered to the field or well, assembled on their bearings so that they may be quickly and properly mounted on the body or shank of the bit.

It is another object of the invention to provide a disk bit that includes two inner disk cutters rotatably carried by a simple unitary bearing. Another object of the invention is to provide as a well drilling bit that includes two outer disk cutters rotatable on supporting bearings, two inner disk cutters rotatably carried on a unitary bearing, and a single member or pin retaining the bearings of the outer cutters on the shank and supporting the bearing of the inner cutters.

Another object of the invention is to provide a bit of the character mentioned having eilec'tive means for locking the removable bearing retaining and supporting pin in position.

A further object of the invention is to provide practical inexpensive, removable bearing units for carrying disk cutters.

Other objects and features of the invention will be best and fully understood'from the following detailed description of typical forms and applications of the invention, throughout which description reference is had to the accompany-- ing drawings, in which:

Fig. 1 is a partial vertical detailed sectional view of one form of the invention, being a View taken substantially as indicated by line l--l on Fig. 2. Fig. 2 is a transverse detailed sectional view taken as indicated by line 22 on Fig. 1. Fig. 3 is a side elevation of the body or shank embodied in the bit illustrated in Figs. 1 and 2. Fig. i is a side or end elevation of one of the outer disk cutters. Fig. 5 is a partial vertical detailed sectional view of another form of the invention. Fig. 6 is a side elevation of the bit illustrated in Fig. 5, and Fig. '7 is a diagrammatic vertical cross section of the lower portion of a well bore illustrating the action of the bit' provided by the invention.

The form of the invention illustrated in Figs. 1

55 to 4 of the drawings includes, generally, a shank or body l0, an inner cutter unit H, two outer cutter units l2, and means I3 for detachably retaining the outer cutter units l2 on the body I0 and for removably supporting the cutting unit I].

The shank or body to is a simple integral 5- structure or member adapted to be attachedto the lower end of an operating string of rotary drill pipe, or the like. Suitable means is provided on the upper end of the body ill for faci'li tating attachment of the body with the drilling 16'' string. In the particular case illustrated in the drawings, a tapered screw-threaded socketv I4 is provided in the upper end of the body ill for receiving a pin ontheidrill collar or other part of the drilling string. shank or body In may be cylindrical or of. round cross section as illustrated throughout the drawings. The body i0 is provided with two downwardly projecting legs Hi to carry the cutter units H and I2. The legs 15 are preferably sub- 20- stantially vertical and have parallel vertical sides. In accordance with the invention, the two legs l5 are laterally offset as illustrated in Fig. .2 of the drawings so that a leading end ofone leg relative to the direction. of rotation of the bit is in 5 advance of the trailing end of the other leg.. The lower ends of the legs l5 may be curved or rounded. Projections or bosses l6 are provided on the outer sides of the legs l5. The bosses 16 are provided to carry the outer cutter units I2 3 and are of round cross section. The horizontal or longitudinal axes of the bosses l6 are normal to the outer. sides of thelegs IS. The bosses .IG are equally spaced between the opposite vertical ends of the legs l5 so that the two bosses 16 5 are horizontally ofiset or out of alignment. Recesses I! are provided in the inner sides of the legs l5. Each of the recesses ll has a straight vertical wall and a straight horizontal wall as clearly illustrated in Fig. 3 of the drawings. 40

The inner cutter unit II is mounted or positioned between the spaced legs l5 of the body and includes two substantially vertical disk cutters l8 and a bearing l9. It is a feature of the present invention that the two disk cutters I8 are rotatable on the single integral bearing IS. The bearing I9 is proportioned to efiectivelyfiti between the two legs [Shaving flat opposite ends adapted to bear against the vertical walls of the recesses ll. An annular radial flange 20 is pro- 5 vided on the bearing IS. The flange 20 is pref-' erably equally spaced from the opposite ends of the bearing. The bearing I9 is treated or hardened to be long wearing and to dependably. carry the rotatable cutters l8.

The upper portion of the 15 The two disk cutters I8 of the inner cutter unit II are revoluble on the bearing I9 at the opposite sides of the flange 20 and have flat inner sides adapted to cooperate with the flange so that inward thrusts on the cutters are effectively transmitted to the flange. Hardened washers 2I surround the end portions of the bearing I9 to receive the outward thrusts from the. cutters I8. The washers 2I seat or fit in the recesses I1 and have straight edges cooperating with the straight Walls of the recesses so that they are held against rotation. The cutters I8 project below the lower ends of the legs I5 and are adapted to engage or act on the formation at the center of the bottom of the wall to form a central dished or concave depression or recess A. The bearing I9 is diametric of the axis of rotation of the bit, and as the cutters I8 are spaced apart by the flange 20, they may leave a very small central core or projection B of formation in the center of the recess A. In accordance with the broader aspects of the invention, any suitable form of cutting parts or edges may be provided on the cutters I8. In the particular embodiment of the invention illustrated in the drawings, series of cutting teeth 22 are provided on the peripheries of the cutters II.

Dowel pins 23 extend through horizontal openings in the legs I5 and project into the recesses I! to cooperate with recesses in the ends of the bearing I9 and washers 2I to prevent rotation of the bearing. The dowel pins 23 are readily removable to permit the easy removal of the inner cutter unit II as 'willbe subsequently described. After the cutters I8 have been assembled on the bearing I9, the washers 2I may be attached or fixed to the bearing in any suitable manner to retain the cutters on the bearing so that the assembly of the bearing and cutters may be handled and transported as a unit. In practice, the washers 2I may be Welded or otherwise fixed to the bearing I9. The outersides of the cutters II may be bevelled inwardly from adjacent the peripheries of the washers 2| so as to have suitable clearance with the inner sides of the legs I5.

The outer cutter units I2 are carried or supported on the bosses I6 and each includes a disk cutter 24 and a removable or detachable bearing 25 for the rotatable cutter 24. The bearings 25 are tubular members adapted to he slid on to the bosses I6. The bearings 25 project outwardly beyond the ends of the bosses I 6 and are provided at their'outer ends with annular radial flanges 26. The inner ends of the bearings 25 may seat against the outer sides of the legs I 5 as illustrated in Figs. 1 and 2 of the drawings. Thrust washers 21 are provided on the inner ends of the bearings 25 and are adapted to seat or bear against the outer sides of the legs I 5. Dowels 28 project from the outer sides of the legs I5 and cooperate with notches or recesses in the washers 21 and bearings 25 to hold the washers and bearings against rotation. The washers 2'! are welded or otherwise suitably fixed to the bearings 25. The bearings 25 and washers 21 are preferably hardened or heat treated.

The cutters 24 are rotatable on the bearings 25 and project downwardly below the lower ends of the legs I5 so as to'act on the formation at the bottom of the well bore. In the particular case illustrated in the drawings, the cutters 24 have flat parallel sides. The inner sides of the cutters 24 bear against the washers 2'! which space the peripheral portions of the cutters from the outer sides of the legs I5. Annular recesses 30 are provided in the outer ends of the cutters 24 to receive the flanges 26 of the bearings. It will be apparent that outward thrusts on the cutters 24 are transmitted to the bearings 25 through the flanges 26. Cutting parts or edges are provided in the peripheries of the outer disk cutters 24. Any suitable or desirable form of cutting parts may be provided on the cutters. In the drawings I have illustrated the cutters 24 provided with helical or spiraled peripheral cutting teeth 3!. The peripheries of the cutters taper outwardly so that the cutting edges of the spiraled teeth 3| taper or slope outwardly. The outer cutters 24 are preferably heavier and larger in diameter than the inner cutters I8. In operation, the outer disk cutters 24 are operable to make an annular cut C in the formation at the bottom of the well bore around the recess A. Due to the location of the cutters 24, the cut C has downwardly and inwardly curved walls extending from the cylindrical side walls of the well bore to the portion of the formation acted upon by the inner cutters I8. The outer cutters 24 project forwardly from the leading ends of the legs I5 and operate to cut or ream the well bore to size.

The means I 3 for detachably retaining the outer cutter units I2 on the bosses I6 and for carrying the inner cutter unit I I includes a pin 35 extending through horizontal openings 36 in the legs I 5. The openings 36 are diametric of the axis of rotation of the bit and are accordingly eccentrio of the bosses I6. The pin 35 extends through a central longitudinal opening 31 in the bearing I 9 to support or carry the bearing and the cut- 3 ters on the hearing. The removable pin 35 projects from the outer side of one leg I5 and its projecting portion carries a plate or head 38. The head 38 engages the outer end of the boss I6 and is welded or otherwise fixed to the pin 35. The head 38 is preferably of slightly less diameter than the washer 28 and its periphery is bevelled. A separable or detachable head 39 engages the end of the boss I6 on the other leg I5. The head 39 has a boss or lug 40 on its inner side extending into the pin carrying opening 36. The head 39 engages against the washer 26 to retain the cut ter unit I2 on the boss I6 and is of substantially the same configuration as the head 38. In accordance with the invention, the head 39 is detachably connected to the pin 35. A cap screw 4| extends through an eccentric opening in the head 39 and is threaded into a longitudinal open ing 42 in the pin 35. The screw 4! has a hollow head which is preferably counter-sunk in the plate or head 39. The invention includes means for removably or releasably locking the screw II in position. A flexible rod 43 is arranged against the head of the screw 4I and has an inner end part held'in a recess 44 in the inner side of the head 39. When the screw M is threaded into the opening 42 of the pin, the rod 43 projects outwardly from the head 39. After the screw has been tightly threaded into position, the projecting end of the rod is bent into the hollow head of the screw to lock the screw in position.

The present invention includes means for flushing the cutters I8 and 24 and for maintaing an effective turbulence or circulation in the bottom of the well bore. the bottom or lower end of the socket I4 and a central fluid passage 46 extends through the body ID from the chamber to discharge between the legs I5 on to the inner cutters I8. Downwardly and outwardly inclined fluid discharge passages A fluid chamber 45 is provided in 7 fl scommunicate with the chamber. 45 and dis charge the circulation fluid downwardly and outwardly on to the cutting parts of the outer" cutters 24. The passages 41 are located so as to'discharge circulation fluid on to the forward orleading portions of the cutters 24. Downwardly and forwardly inclined fluid passages '48 extend through the legs I and discharge at the forward lower ends of the legs. The circulation fluid under pressure discharging from the passages 48 is efiective in maintaining proper turbulence in the lower portion of the well bore. Choke pipes or nozz1es49may be provided in the discharge end of each of the passages, 41, and 48.

In assembling the bit illustrated in Figs. 1 to 4 inclusive of the drawings, the assemblies of the inner cutters l8 and their bearings I9, and the assemblies of the outer cutters 24 and their bearings are adapted to be handled as units. The inner disk cutters l8 are retained on the bearing I 9 by the washers 2| so that the assembly may be readily handled without danger of displacement of the cutters. The outer cutters 24 are held on their respective bearings 25 by the washers 21 and flanges 26. When the cutters are to be mounted on the body, the bearing 25 carrying one of the cutters 24, is slid on to one of the bosses 16 and the pin carrying the head 38 is passed into the opening 36. The inner cutter unit is inserted between the legs l5 and held in position so that the pin 35 may be passed through the opening 31 in the bearing 19. After the pin 35has been positioned so that its head 38 seats against the boss [8, the other outer cutter unit I2 'is arranged on the other boss l6 and the head 39 is arranged against the boss IE to lock the cutter unit in position. The screw4l may then be threaded into the opening 42 and locked in place by the rod 43 in the manner described above. The dowel pins 23 aid in positioning the inner cutting unit so that theopeni-ng 31 is in proper registration with the portions of; the opening 36 in the two legs 15. It will be apparent how the cutter units II and I2 may be easily and quickly secured in their proper positions on the bit. A simplewrench for engaging the screw 4! is the only tool'required in the assembling of the hit. As the cutters l8 and 24 are assembled on-their bearings at the place of manufacture, the proper fitting of the parts is assured;

In operation, the bit is rotated onthe lower end of an operating string in'the usual manner and the independently'rotatable disk cutters 24 and I8 act on the formation at the bottom .7 of the bore. The outer cutters 24 project downwardly and forwardly from the legs I5 to cut the bore to size and to make the annular cut 0 in the bottom of the bore. The inner cutters H3, in being carried by the diametric bearing l9, project from the lower ends of the cutters l5 to cut the recess A in the formation. The heads 38 and 39 and the pin 35 are held against rotation by the relative eccentricity of the pin 35 and bosses IS. The end thrusts to which the cutters l8 and 24 are "subjected are efiectively taken by the flanges and washers on the bearings l9 and 25 in the manner described above. The circulation fluid discharging from the fluid passage 46 is effective in the flushing of the ingner cutters 18, while the fluid discharged from the passages 41 flushes the outer cutters 24. The bit is inexpensive and easy to assemble, and very effective in operation. I

The form of theinvention illustrated in Figs. 5 and 6 of the drawings includes a body Ill an turning.

inner cutter unit 1 I, enter cutter units 42 and means I3 for supporting the inner cutter unit ll and for detachably retaining the outer cutter'units l2 on the .body.

The body Ill is similar to the body [0 described above, having spaced projectinglegs I5 at its lower end. .A tapered-screw threaded pin is provided on the upper end of the body M to facilitate connection of the bit with the operating or drilling string. The legs I5 have flat vertical sides and are laterally offset in the same manneras the legs. [5. The inner cutter unit I l is substantially identical with the cutter unit ll including, an integral bearing l9 and two disk cutters I8. The bearing. I9 fits between the two legs l5 and'has 'a central radial flange 20 Washers 21 are welded or otherwise fixed to the end parts of the bearing l9 and seat in recesses in the inner sides of the legs l5 The cutters l8 are rotatable on' the bearing between the flange 29 and washers 2M- The bearing I9 is diametric'of the axis of the'bit and the cutters l8 project fromthe lower ends of the legs I5 to acton the formation at the bottom of the well bore.

The outer-cutter units I2 are supported on the bosses lt -at the outer sides of the legs l5 Each outercutter unit I2 includes a bearing 62 and a cutter 24 The bushings or bearings 62 are threaded on the bosses 60 and have closed ends 63 covering'the ends of the bosses. Outwardly projecting annular flanges 64 are provided on the outer end of each bearing 62 and a washer 65 is fixed on the inner end of each bearing and seats against the outer side of a leg I5 The disk cutters 24 areirotatable on the bearings 62 between the flanges 64' and washers 65. The cutters 24 projectforwardly from the leading ends of the legs 15 and downwardly from the lower ends of the legs. The outer cutters 24 may. be 'in the nature ofplain disk cutters having smooth tapered peripheries and comparativelynarrowperipheral cutting'edges 66. The washers 65 and the bearings 62 to which the washers are attached may be held against rotation by dowels 61.

The means I 3 operates to removably retain the outer cutter units '12 on the bosses l6 and to support the removable inner cutter unit I l The means l'd includes screws 18 passing through concentric openings in the ends 63 of the bearings 62 and concentric openings 1! in the bosses l (i The inner ends of the screws 10 are threaded into openings 13 in the opposite ends of the bearing lfi The two openings 13 are eccentric so that the bearing is positively held against rotation. Means is provided for locking the screws 10 in position. Lockwashers-or ear Washers are arranged under the heads of the screws and each has one or more ears l5 cooperating with recesses 16 in the outer ends 63 of the bearings 62. Other ears (50f the washers seat against the flat sides of the screw head to hold the screw against The body H3, is provided with circulation passages for discharging circulation fluid to flush the cutters l8 and 24 and to maintain circulation in the bottom of the well bore. A vertical fluid passage 85] extends through the pin 60 and terminates in a chamber 8'! in the body M A central passage 82 extends downwardly from the chamber 3| and discharges fluid between the legs [5 to flush the cutters l8 -Downwardly and outwardly inclined fluid passages 83 extend from the chamber 8| and discharge fromv the exterior of the body at points above the outer cutters 24 Passages 85 extend downwardly through the body ll! from the chamber 8| to discharge at the lower forward ends of the spaced legs I5 The fluid discharging from the passages 86 maintains an efiective turbulence and circulation in the bottom of the bore. Choke pipes or nozzles 86 may be provided in the discharge ends of the several fluid passages.

The operation of the bit illustrated in Figs. 5 and 6 of the drawings is the same as the operation of the bit illustrated in Figs. 1 to 4 inclusive. In assembling the tool, the bearings 62 carrying the cutters 24 are first threaded on to the bosses Ili The inner cutting unit H is then positioned between the legs l5 so that its openings 13 register with the openings H. The screws 10 are then passed through the openings H and threaded into the openings 13 to lock the bearings 62 in position and to support the inner bearing 19*. The screws may be readily locked in place by bending the ears 15 of the lock washers into the recesses 16. It will be apparent how the cutter units H and 12 may be easily and quickly detached after removing the screws 10.

Having described only typical forms and applications of my invention, I do not wish to be restricted or limited to the specific forms and applications herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. A well drilling bit including, a body having projecting legs on its lower end, bosses on the outer sides of the legs, a cutter unit positioned between the legs, cutter units supported on the bosses, and a single means supporting the first mentioned unit and retaining the other units on the bosses.

2. A well drilling bit including, a body having projecting legs on its lower end, bosses on the outer sides of the legs, a cutter unit positioned between the legs, cutter units supported on the bosses of the legs, and a single pin supporting the inner cutter unit and retaining the other units on the bosses.

3. A well drilling bit including, a body having spaced legs projecting from its lower end, projecting bosses on the outer sides of the legs, removable disk cutter units on the bosses, an inner disk cutter unit positioned between the legs, there being aligned transverse openings in the legs and bosses, and a removable pin extending through the openings and supporting the inner cutter unit and having heads retaining the first mentioned units on the bosses.

4. A well drilling bit including, a body having spaced legs projecting from its lower end, a bear ing between the legs having its ends bearing against the inner sides of the legs, a flange on the bearing between its ends, washers fixed on the end portions of the bearing, the washers having fiat edge portions cooperating with correspondingly shaped parts on the legs to hold the bearing against rotation, cutters rotatable on the bearing between the flange and washers, and means detachably supporting the bearing on the legs.

5. A well drilling bit including, a body having spaced legs projecting from its lower end, a bearing between the legs, bosses on the outer sides of the legs, bearings on the bosses, cutters rotatable on the bearings, there being openings in the legs and bosses eccentric to the bosses, a removable pin extending through said openings and a longitudinal opening in the first mentioned bearing, and heads on the pin retaining the bearings 0n the bosses.

6. A well drilling bit including, a body having 5 spaced legs projecting from its lower end, a bearing between the legs, bosses on the outer sides of the legs, bearings on the bosses, cutters rotatable on the bearings, there being openings in the legs and bosses eccentric to the bosses, a removable pin extending through said openings and a longitudinal opening in the first mentioned bearing, and heads on the pin retaining the bearings on the bosses, one of the heads being detachable to permit removal of the pin.

7. A well drilling bit including, a body, spaced downwardly projecting legs on the body, a removable one piece bearing between the legs having a radial flange between its ends, washers fixed to the bearing and spaced from the opposite 20 sides of the flange, cutters rotatable on the bearing between the flange and washers, and means removably supporting the bearing between the legs in a position where the cutters project downwardly below the ends of the legs.

8. A well drilling bit including, a body, spaced downwardly projecting legs on the body, the legs being laterally ofiset, bosses on the outer sides of the legs, removable bearings on the bosses, revoluble cutters retained on the bearings, a re- 30 movable bearing between the legs having a 10ngitudinal opening, a revoluble cutter on the last named bearing, there being openings in the legs and bosses diametric of the axis of rotation of the body and eccentric of the bosses, a removable 35 pin extending through the last mentioned openings and the opening in the said bearing, and means on the pin for retaining the first mentioned bearings on the bosses.

9. A well bit including, a body, spaced legs projecting from the body having projecting bosses on their outer sides, bearings threaded on the bosses, the bearings having ends covering the ends of the bosses, cutters rotatable on the bearings and projecting beyond the lower ends of the legs, there being transverse openings in the legs extending through the bosses, a removable cutter carrying bearing between the legs, and screws engaging said ends of the bearings passing through said openings and threaded into eccentric openings in the last mentioned bearing to lock the first mentioned bearings on the bosses and to support the last mentioned bearing.

10. A well bit including, a body, spaced legs projecting from the body having projecting bosses 55 on their outer sides, bearings threaded on the bosses, rotatable cutters on the bearings and projecting beyond the lower ends of the legs, there being transverse openings in the legs extending through the bosses, a removable cutter carrying bearing between the legs, and members passing through said openings and threaded into eccentric openings in the last mentioned bearing to support it and engaging the first mentioned bearings to lock them on the bosses.

11. In a well bit, a body, spaced legs projecting from the lower end of the body, there being recesses in the inner sides of the legs, having fiat wall portions, a removable bearing between the legs having its ends bearing against the inner walls of the recesses, washers rigidly attached to the bearing and having fiat faces cooperating with said fiat wall portions of the recesses to hold the bearing against rotation, means removably supporting the bearing, and a cutter rotatable on the bearing and projecting from the lower ends of the legs.

12. In a well bit, a body, spaced legs projecting from the lower end of the body, there being recesses in the inner sides of the legs having fiat wall portions, a removable bearing between the legs having its ends bearing against the inner walls of the recesses, washers rigidly attached to the bearing and having fiat faces cooperating with said wall portions of the recesses to hold the bearing against rotation, a radial flange on the bearing spaced between the washers, cutters rotatable on the bearing between the flange and washers and projecting beyond the lower ends of the legs, and a, removable member supporting the bearing.

13. A rotary well bit including, a body, two spaced legs projecting from the lower end of the body, the legs being laterally offset in the direction of rotation of the body, projections on the outer sides of the legs, removable bearings on the projections, disk cutters on the bearings projecting from the lower ends of the legs and rotatable about axes laterally offset in the direction of rotation of the body to project forwardly beyond the leading edges of the legs, and spaced disk cutters between the legs rotatable on an axis diametric of the axis of rotation of the body and projecting beyond the lower ends of the legs.

14. A rotary well bit including, a body, twospaced legs projecting from the lower end of the body, the legs being laterally offset in the direction of rotation of the body, projections on the outer sides of the legs, removable bearings on the projections, disk cutters on the bearings projecting beyond the lower ends of the legs and rotatable about axes laterally offset in the direction of rotation of the body to project forwardly beyond the leading edges of the legs, a removable bearing between the legs having a longitudinal axis diametric of the axis of rotation of the body, a radial flange on the bearing lying in the plane of the axis of rotation of the body, and a disk cutter rotatable on the bearing at each side of the flange and projecting downwardly below the lower ends of the legs.

15. A rotary well bit including, a body, two spaced legs projecting beyond the lower end of the body, the legs being laterally offset in the direction of rotation of the body, projections on the outer sides of the legs substantially equally spaced between the leading and trailing edges of the legs, removable hearings on the projections, rotatable cutters on the bearings projecting beyond the lower ends of the legs and forwardly beyond the leading edges of the legs, a removable bearing between legs, a cutter rotatable on the bearing and projecting downwardly beyond the lower ends of the legs, and means retaining the bearings on the legs so that the assemblies of the bearings and cutters are replaceable as units.

16. A Well drilling bit including a body having projecting legs on its lower end, a projecting boss on the outer side of a leg, a removable bearing on the boss, a cutter rotatable on the bearing,

a bearing between the legs, a cutter rotatable on 9 the second mentioned bearing, and a removable member holding the first mentioned bearing against displacement from the boss and supporting the second mentioned bearing.

JOHN H. HOWARD. 

